1. Field
Non-limiting example embodiments of the present invention relate to engine load estimation for an internal combustion engine. Engine load can be represented by a change in air mass at an inlet manifold of an internal combustion engine.
2. Related Art
In a modern engine, an amount of fuel to be injected into a cylinder in a given cycle for a given lambda value is related to the air mass for the cycle at an intake manifold for the cylinder. In a normally aspirated engine, the air mass at the intake manifold is in turn related to the airflow at the throttle. However, in a supercharged engine provided with a supercharger bypass path, the airmass available is also dependent on whether the supercharger bypass path is open or not. Typically, the bypass valve, which may for example be in the form of a butterfly valve, is controlled based on inlet manifold pressure, and a particular timing of the opening and closing of the bypass value may not readily be determined.
Air mass measurement sensors are known, but they typically react relatively slowly. Accordingly, direct measurement of air mass at an intake manifold may not be able to act sufficiently quickly in a dynamic engine operating environment.
Accordingly, there is a need for a mechanism for estimating changes in air mass at an inlet manifold.